Sound-producing instrument



DE ELBERT A. REYNOLDS SOUND PRODUCING INSTRUMENT Filed Oct. 26, 1920 2% I 2 I 23 M o I 19 3 ,9

Ei' E1 Patented Feb. 10, 1925.

UNITED STATES PATENT OFFICE.

DE ELBERT A. REYNOLDS, OF YONKERS, NEW YORK, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AUDIPHONE COMPANY OF AMERICA, OF NEW TION OF DELAWARE.

YORK, 1v. Y., A CORPORA- SOUND-PRODUCING INSTRUMENT.

Application filed 0'ctober 26, 1920. Serial No. 419,575.

State of New York, have invented certain new and useful Improvements in Sound- Reproducing Instruments, of which the fol lowing is a specification.

An object of this invention is to provide an improved, simple and effective means for magnifying the vibration of a diaphragm within an appropriate sound chamber under proper acoustic conditions to mechanically and electrically reproduce speech or sound waves electrically conveyed to the instrument, delivered in a magnified or amplified volume, with means for regulating the volume and intensity of the sound reproduced, controlling its quality, timber and rotundity and adapted to control or modulate both mechanically and electrically sound" waves emanating from a telephone, phonograph, violin, horn or other instrument. 1

To accomplish this purpose, I prefer to use an electro-magnet attached to one pole of a permanent magnet, so arranged as to bring the free end of the core of the electromagnet in close proximity with the free pole of the permanent magnet that the flow of magnetic flux may always be as free and strong as possible, and attaching by means of a pivot or pin a. short thick armature to the free end of the permanent magnet, allowing it to extend over and become attuated by the electro-magnet.

On the free end of the armature. I prefer to place a 'hook or attachment for engaging a lever held substantially parallel to such armature, one end of such lever being pivotally connected with a diaphragm, and

the other end with. an adjustable screw for regulating the proximity of the armature to the core of the electro-magnet, as by means of a link or rod, and the lever being provided with a notch or groove to prevent the link or rod from slipping, and for the further purpose of keeping the working parts permanently in alignment;

I prefer to encasethe diaphragm 111 a non-magnetic metal case with a large opening beneath, rigidly attached to the permanent magnet by means of a standard, provided with a lug, fitted between the two prongs or legs of the {permanent magnet, and held rigidly by means of a clamp and screw. v

The -sound chamber above the diaphragm is preferably made by the attachment of a front plate, with the inner surface plain, corrugated or recessed to suit the purpose for which any particular instrument may be intended, such variations being made to serve as a mufller or air-cushionin the re production of harsh articulations, or for such modifications as may be found desirable in the transmission and amplification of speech or music. The front plate is also provided with openings, over which I place an adjustable plate, lined with felt, or other sound proof material with similar openings, held in place by a ferrule or nut. Such chamber can be conveniently formed by screwing the front plate into the flanges of the diaphragm case, clamping the periphery of the diaphragm between suitable Washers or cushions and holding the front plate at the desired tension upon the diaphragm by means of a set screw. I have discovered that the form of the sound chamber with its adjustable openings, in connection with a diaphragm however actuated, affords awide range of modulation in both timber and rotundity, whether in connection with a diaphragm operated mechanically, as with a stylus as in a phonograph, or electrically as with an electro-magnet as in a receiver or vibratory as in the ordinary transmitter.

I find that a short, thick armature, with one end resting upon one leg of the permanent magnet and the other adjustable to the closest proximity of the pole of the electromagnet so nearly completes the magnetic circuit as to make the electro-magnet unusually powerful and well adapted to electro-mechanical amplification.

Further features and objects of the invention will be understood from the following description and the accompanying drawings, in which Fig. 1 is a central longitudinal section of one form of my invention;

Fig. 2 is a transverse section on line 2-2 of Fig. 1, viewed in the direction of the indicating arrows;

'nent magnet.

Fig. 3 is a top plan view of Fig. 1, with the horn or other external sound passage means omitted;

Fig. 4 is a detail side elevation of certain parts of Fig. 1; and

Figs. 5 and 6 are side and top plan detail views of a. modified form of permanent and electric magnets.

In the drawings, forming a. part of my specification, 1 represents a permanent magnet of the horse-shoe variety, with one pole considerably longer than the other, to which is permanently attached the core of an electro-magnet 2, the core extending from the long leg of the permanent magnet into close proximity with the short leg of the perma- 3 represents a short, thick armature of soft iron held firmly to the short leg of the permanent magnet by magnetic force, and prevented from dislocation by a small pin preferably attached to the armature and working freely in an opening in the upper surface of the short leg of the permanent magnet.

at is a lever connecting-at its one end with a screw rod 5, leading to diaphragm 6, and at its other end to the adjustable screw rod 7. 8 is a countersunk screw-nut attached to the screw rod 7, designed to regu late the armature 3 through the lever 4 and link or rod 9. The lever 4 is provided with a notch or groove 4 to prevent the link or rod 9 from slipping, and also whereby the link 9 actuates the lever 4 through a lever arm which is substantially constant for different positions of adjustment set by the adjusting means comprising the screw rod 7 and the nut 8. It will be further noted that the direction of adjustment effected by the adjusting means is in the direction, i. e., parallel thereto, of the direction of actuation of the diaphragm. In the specific form of the invention shown in the drawings, the actuating mechanism comprises a minimum number of parts, movably connected to one another at substantially constant points; in such preferred embodiment, the parts of the actuating mechanism are arranged substantially in a common plane and the adjusting means constructed to provide movement of adjustment in such common plan-e, whereby adjustment is positively and directly effected, thereby practically attaining delicate regulation of volume or intensity, without destroying the quality, timber and rotundity of the sounds emitted.

10 is a. set-screw for holding the faceplate 11 at a. proper tension upon the diaphragm, the face-plate being provided with a threaded extension 12 to receive a horn attachment or other device, and upon which is held the adjustable plate 13. The faceplate is also provided with arcuate openings 17, 17. 17, 17 connecting with the sound chamber 14, for the purpose of releasing any air under undue compression in proximity of the location of theopenings 17; the face plate carries an adjustable plate 13, lined with a felt or other sound-proof material, and having similar arcuate openings, which upon arcial adjustment of more or less register, constitutes means for regulating the extent of opening of the openings in the face-plate in whole or in part. I

18 is a non-magnetic metal case, or of rubber or fibre composition, containing a recess for receiving the diaphragm 6. The diaphragm case is rigidly attached to the permanent magnet 1 by means of a standard 19, lug 20, clamp 21 and screw 25. 22 is a box or receptacle of insulating material or composition, with interior lugs 23, 23, 23, 23 for fastening the diaphragm case 18 to the receptacle. The terminal screws 24, 24, serve to connect the wires of the electro-magnet 2 with induction coils, relays, line wires or such other exterior sources of current as may be found desirable.

Means are also provided for securing the non-magnetic metal case 18 to the box or receptacle such as screws 26 passing through the rim of the case 18 into lugs 23, 23, etc. Any desired number of external lugs 27 may be employed for fastening the box or receptacle 22 to a Wall, desk, or other support.

Tn Figures 5 and 6, T have shown a modification in the construction and arrangement of the tro-magnet, employing for simplification in manufacture a set (two being shown) of permanent magnets 30, 31, disposed side by side with the block 32 of soft iron between the short legs of the permanent magnets and block 33 between the curved portions of the permanent magnets. The permanent magnets 30, 31 are preferably laminated in planes substantially parallel to the direction of length of the magnets, as indicated in Fig. 6. The core 34 of the electro-magnet 35 is cut away or recessed at 36 to be received between the long legs of said permanent magnets 30, 31 thereby forming a substantially integral connection with the poles and legs of said permanent magnets 30, 31. The core 34 of the electro-magnet 35 is laminated and preferably in planes substantially at .right angles to the plane of laminations of the respective legs of the permanent magnets 30, 31, whereby highly improved clarity and amplification of the reproduced sounds are attained.

From the above it will be observed that the device is especially adapted to loud speaking receivers for announcing trains, paging, for equipment on trains for announcln stations, transmission of music, advertising and other uses. In the use of the invention in connection with a sensitive transmitter, as in theequipment in churches,

permanent magnet and the electheatres, and large halls, a plurality of such devices is distributed in suitable parts of the auditorium for the purpose of equalizing articulation, whereby amplified reproduction is obtained at any point in such auditorium, simultaneously from all such devices.

lVhe-reas I have described my invention by reference to specific forms thereof, it will be understood that many changes and modifications may be made without depart.- ing from the invention, as defined by the appended claims.

I claim.

1. A sound reproducing instrument comprising a diaphragm, a lever for actuating said diaphragm, a permanent magnet, an electro-magnetic coil, an armature connected to said lever for actuating the same and a core for said electro-magnetie coil for actuating said armature, said core being formed of laminations extending substantially at right angles to the direction of length of said permanent magnet. y

2. A sound reproducing instrumentcomprising a diaphragm, a lever for actuating said diaphragm, a permanent magnet formed of laminations extending substantially parallel to the direction "of length of said permanent magnet, an electro-magnetic coil, an armature connected to said lever for actuating the same and a core for said electro-magnetic coil for actuating said armature, said core being formed 0 laminations extending substantially at right angles to the direction of length of said permanent magnet. v

3. A sound reproducing instrument comprising a diaphragm, a lever for operating said diaphragm, an armature for operating said lever, a permanent magnet having a short leg and a long leg, said armature being magnetically pivoted on said short leg, an electro-magnetic coil mounted ad acent to and extending transversely of the direction of length of said long leg of said permanent magnet, and a core for and enclosed by said electro-magnetic coil, said core being formed of laminations extending substantially at right angles to the direction of length of said long leg of said permanent magnet.

4. A sound reproducing instrument comprising a diaphragm, a lever for operating said diaphragm, an armature for operating said lever, a permanent magnet having a short leg and a long leg, said armature being magnetically pivoted on said short leg, an electro-magnetic coil mounted adjacent to and extending transversely of the direction of length of said long leg of said permanent magnet, and a core for and enclosed by said electro-n'iagnetic coil, said core being formed of laminations extending in planes substantially at right angles to the direction of length of said long leg of said permanent magnet.

5. A sound reproducing instrument comprising a diaphragm, an arm carried by said diaphragm, a lever connected to said arm, an armature controlling said lever and electro-magnetic means controlling said armature, said electro-inagnetic means comprising a permanent magnet embodying laminations disposed in a predetermined plane, a coil and a core for said coil, said core embodying laminae of magnetic material disposed in a plane substantially at right angles to said predetermined plane.

S. A sound reproducing instrument comprising a diaphragm, a lever for operating said diaphragm, an armature controlling said lever and electro-magnetic means controlling said armature, said electro-magnetic means comprising a plurality of spaced permanent magnets, a coil and a core common to said plurality of permanent magnets and formed of laminae extending in planes substantially at right angles to the direction of length of one of saidpermanent magnets.

"7. A sound reproducing instrument compris ng a diaphragm, a lever for operating said diaphragm, an armature controlling said lever and electro-magnetic'means controlling said armature, said electrmmagnetic means comprising a plurality of spaced, substantially parallelly arranged permanent magnets, a coil and a core common to said plurality of permanent magnets and formed of laminae extending in planes substantially at right angles to the direction of length of both of said permanent magnets.

A sound reproducing instrument comprising a diaphragm, a lever for actuating said diaphragm, an armature for actuating said lever and electro-magnet-ic means con trolling said armature, said electro-magnetie means comprising a plurality of spaced laminated permanent magnets, a coil coacting in common with said permanent magnets, and a core for said coil, said core being formed of laminae extending substantially at right angles to the plane of lamination of one of said permanent magnets.

9. A sound reproducing instrument, comprising a diaphragm, a lever for actuating said diaphragm, an armature for actuating said lever, a ermanent magnet having a long leg and a s ort leg, said armature being pivoted relative to said short leg, an electromagnetic coil and a core for said electromagnetic coil formed of laminations having a portion thereof in close magnetic adjacency to the end of said long leg of said permanent magnet and extending substantially at right angles to the direction of length of said long leg.

10. A sound reproducing instrument, comprising a diaphragm, a lever for actuating said diaphragm, an armature for actuating said lever, a permanent magnet having a long leg and a short leg, said armature being pivoted relative to said short leg, an

' electro-magnetic coil, a core for said electro-magnetic coil formed of laminations having a portion thereof in close magnetic adjacency to the end of said long leg of said 

